<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width">
    <title>Document</title>
    <style>
        table tr td{
            width: 50px;
            height: 30px;
            text-align: center;
        }
    </style>
</head>
<body>
    <table border="1" style="border-collapse: collapse;">
        <tr>
            <td>1 </td>
            <td>2 </td>
            <td colspan="2">3 </td><!--colspan跨列合并 -->
            <!--td>4 </td-->
            <td>5 </td>
        </tr>
        <tr>
            <td colspan="3">6 </td>
            <!--td>7 </td>
            <td>8 </td-->
            <td>9 </td>
            <td rowspan="3">10 </td>
        </tr>
        <tr>
            <td>11 </td>
            <td rowspan="2">12 </td>
            <td>13 </td>
            <td>14 </td>
            <!--td>15 </td-->
        </tr>
        <tr>
            <td>16 </td>
            <!--td>17 </td-->
            <td>18 </td>
            <td>19 </td>
            <!--td>20 </td-->
        </tr>

    </table>